In an attempt to clear out the clutter, Google decided to disable a handful of old services that have been replaced by newer options or simply aren't needed anymore. This includes Google Sync, Google Calendar Sync, the Issue Tracker API, SMS event scheduling, and a few more. This may sound awful, as sync is an important part of Google's services and something they do well, but calendars already sync (and still will sync) with CalDAV just like contacts will with CardDAV and so on. These open-source technologies will now take precedent over previously used proprietary ones like Microsoft Exchange (which we've talked about before). For more details, hit up the Official Google Blog.